Nowadays, motion picture techniques can enrich the audiovisual document and what the spectator feels. Equipment is added to the seat on which the spectator is sitting to provide them with other sensations than those provided by sight and hearing. Hence, the seats can now move along several axes of freedom causing the spectator to move in relation to the visual and/or audio content. The spectator perceives synchronised sensations with images and/or sounds present in the audiovisual document. His immersion in the reproduction of the document is thus greater and his impression of living the event more intense. For example, in the case of a film shot at the front of a roller coaster, when a drop is reproduced on the screen of the cinema, the seat of the spectator moves slightly forward. Another example consists in strongly vibrating the seats of the cinema from left to right during the reproduction of a scene.
The audiovisual contents with haptic enhancement are used to control actuators that move the spectator during the reproduction of the document. During the reproduction, the different audio tracks, video, text to insert, etc. are read. In the case of a document with haptic enhancement, a track being part of the audiovisual document contains the parameters defining the haptic effect to generate. These parameters are a list of commands to apply to the different actuators available by the spectator during the reproduction of the document.
Most frequently, the haptic enhancements are added for films already realised. An operator views the film and determines a sequence whose perception would be reinforced for the spectator by a movement carried out on his person. The operator determines manually the movement type (movement, vibration, ticking, trepidation, etc.) and programmes the activation of specific actuators during this sequence. The haptic parameters are added to the video signals and possibly audio on a specific support. During the reproduction, the haptic parameters are read and transmitted to the actuators responsible for applying stimuli to the spectator. These stimuli can generate all sorts of sensations: well-being, fear, confidence, smallness, dizziness, etc.
Currently, these haptic parameters are calculated manually by an operator viewing the video or audiovisual document. There is therefore a real need for a new technique able to automate the creation of haptic actuator control parameters and the enhancement of new video documents.